1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CRYPTO_SECURE_HASH_H_
6#define CRYPTO_SECURE_HASH_H_
7
8#include <stddef.h>
9
10#include <memory>
11
12#include "base/macros.h"
13#include "crypto/crypto_export.h"
14
15namespace crypto {
16
17// A wrapper to calculate secure hashes incrementally, allowing to
18// be used when the full input is not known in advance.
19class CRYPTO_EXPORT SecureHash {
20 public:
21  enum Algorithm {
22    SHA256,
23  };
24  virtual ~SecureHash() {}
25
26  static std::unique_ptr<SecureHash> Create(Algorithm type);
27
28  virtual void Update(const void* input, size_t len) = 0;
29  virtual void Finish(void* output, size_t len) = 0;
30  virtual size_t GetHashLength() const = 0;
31
32  // Create a clone of this SecureHash. The returned clone and this both
33  // represent the same hash state. But from this point on, calling
34  // Update()/Finish() on either doesn't affect the state of the other.
35  virtual std::unique_ptr<SecureHash> Clone() const = 0;
36
37 protected:
38  SecureHash() {}
39
40 private:
41  DISALLOW_COPY_AND_ASSIGN(SecureHash);
42};
43
44}  // namespace crypto
45
46#endif  // CRYPTO_SECURE_HASH_H_
47